Keyboard chassis assembly



A ril 30, 1963 F. M. LUND 3, 7,

KEYBOARD CHASSIS ASSEMBLY Filed July 14, 1960 3 Sheets-Sheet 1 A J EN 0-54 1 5/ i BY 36 H' y dmr April 30, 1963 F. M. LUND KEYBOARD CHASSISASSEMBLY 3 Sheets-Sheet 2 Filed July 14, 1960 INVENTOR.

April 30, 19-63 F. M. LUND 3,087,363

KEYBOARD CHASSIS ASSEMBLY Filed July 14, 1960 5 Sheets-Sheet 3 mmgwwg.

BY I

ZJM-X%M c United States Patent 3,ii37,368 KEYEGARD CHASSES ASEMLY FrankM. Land, Chicago, Rik, assigner, by mesne assignments, to Pratt, Read 8:$0., Essex, Conn, a corporation of Qonnecticut Filed July 14, 1960, Scr.No. 42,82d 22 Claims. (6!. $4423) This invention relates to keyboardmusical instruments, such as organs, accordions, pianos, and the like.

Keyboards are generally constructed of individually pivotally mounted,spring-biased black and white key units. Each key unit comprises anouter hollow key piece made of a suitable plastic material having thenecessary size, shape and color for the key involved and a wooden ormetal core acting as a lever or connecting arm of the key. In both typesof key units, the hollow key piece is secured to the core by securingmeans arranged and located in such a manner that it is impossible toseparate each key piece from the associated core in the assembledkeyboard without first removing the entire key unit from the keyboardassembly. This complicates servicing and fabrication problems. Forexample, during the assembly of the keyboard, it sometimes occurs that akey piece becomes damaged requiring its replacement. With the prior keyunit constructions, appreciable time is wasted in removing the entirekey unit so that a new key piece cm be substituted for the damaged one.

The hollow key pieces have commonly been made of synthetic thermosettingplastic materials which are expensive relative to thermoplasticmaterials. The latter type of material has, heretofore, been foundunsatisfactory for use as hollow key pieces mainly for the reason thatit readily becomes deformed through use.

It is an object of the invention to provide a key unit construction forthe keyboards of musical instruments wherein the hollow key piecethereof may be easily removed from the core thereof without requiringthe removal of the entire key unit from an assembled keyboard.

Another object of the invention is to provide a unique key unitconstruction using key pieces made of a thermoplastic material and metalcores which are so constructed and related to the key pieces that thethermoplastic key pieces maintain their shape indefinitely under normalusage.

Still another object of the invention is to provide an improved keyboardassembly comprising a simple and compact unitary chassis upon which alarge number of key units may be quickly and easily assembled. A relatedobject of the invention is to provide a keyboard chassis as justdescribed provided with simple means for holding the key units againstlateral movement and means for limiting the upward vertical movementthereof. A related object of the invention is to form the last twomentioned means for each key unit as a single element on the chassis tosimplify the construction of the chassis and to render the same moreeffective to carry out their intended functions.

An overall object of the present invention is to provide an improvedassembly of a keyboard chassis and key units which are constructed andarranged to provide an extremely rugged and simply constructed keyboardchassis assembly.

In accordance with the most preferred form of the invention, thekeyboard chassis assembly includes a chassis member having a frontmarginal wall from the top of which extend a first series oflongitudinally-spaced, upwardly projecting fingers, and a rear,marginal, fulcrumforming wall from the top of which extend a secondseries of longitudinally-spaced upwardly projecting fingers. Theselatter series of fingers are respectively positioned in transversealignment to the first mentioned series of fingers at the front of thechassis member. The chassis member is further provided with a series ofspring anchoring lugs struck from the chassis member, one such lug beingpositioned opposite each of the fingers on the fulcrum-forming wall.

The key units making up the keyboard (sometimes also referred to as keyassemblies) extend between corresponding pairs of said fingers at thefront and rear of the chassis member, which fingers fix the position ofthe key units on the chassis member. Each key unit most advantageouslycomprises a channel-shaped metal core or lever arm having flangesextending downwardly from a connecting web. The flanges of each leverarm straddle the corresponding front and rear chassis fingers, thelatter fingers forming lateral stops for the key unit involved. Theflanges are provided with inverted V-shaped slots which form fulcrumpoints which are pivotally mounted upon the upper marginal edge of saidfulcrum-forming wall. A tension spring extends between each springanchoring lug of the chassis member and the associated lever arm at apoint rearwardly of the fulcrum-forming wall to bias the front end ofthe associated lever arm upwardly.

Adjustable elevation limiting means are provided for each key unit andpreferably are formed by said lateral stop fingers at the front of thechassis member. These fingers are turned back at the tops thereof toform rearwardly projecting extensions around which a strip of felt orother noise deadening material is bent and adhesively or otherwisesecured. Each horizontal finger extension is located between the flangesof a key unit lever arm, and acts as a vertical stop or abutmentshoulder. One (or both) of the flanges of the lever arm is provided withan inwardly extending stop lug located at or near the bottom of theflange and this stop lug abuts against the bottom of the associatedchassis finger projection to limit the upward movement of the lever arm.Minor adjustments in elevation of the control lever may be made bybending the associated chassis finger extension up or down a limitedamount.

Each key unit includes a hollow key piece preferably made of a moldedthermoplastic material and having depending side flanges which closelystraddle the flanges of the associated lever arm. The hollow key piecetits tightly around the web and flanges of the associated lever armwhich thereby maintain the shape of the key piece. Each key piece isremovably anchored to its lever arm preferably by means comprising ascrew passing through the top of the rear end portion of the key piece(which is normally hidden from view by the casing or frame of themusical instrument involved) and threading into the web of theassociated lever arm. The forward end of the lever arm is mostadvantageously provided with a tongue which fits snugly into a slotformed in an internal rib in the front portion of the key piece, so thatboth the front and rear portions of the key piece are anchored in place.The key piece may be simply removed from its lever arm by removing thescrew from the rear end portion of the key piece and then sliding thekey piece forwardly to remove the tongue from the aforesaid slot. It isapparent that, with such a key unit construction, each key piece can beremoved from its associated control lever without removing the controllever from the chassis member.

Other objects, advantages and features of the invention will becomeapparent upon making reference to the specification to follow, theclaims and drawings wherein:

FIG. 1 is a fragmentary perspective view of an organ keyboard chassisassembly constructed in accordance with one form of the presentinvention;

FIG. 2 is an exploded view of the two main component parts making up awhite organ key unit used in the keyboard chassis assembly of thepresent invention;

FIG. 3 is a fragmentary perspective View of the front portion of a whitekey piece on an enlarged scale;

FIG. 4 is an enlarged fragmentary bottom plan view of an assembled whitekey unit;

FIG. 5 is a perspective view of a black key piece used in the keyboardchassis assembly of the present invention on an enlarged scale;

FIG. 6 is a vertical sectional view through a white key piece of thekeyboard chassis assembly of FIG. 1, taken substantially along the line66 therein;

FIG. 7 is a vertical sectional view through a black key piece of thekeyboard assembly of FIG. 1, taken substantially along the line 77therein;

FIG. 8 is an enlarged transverse section through the keyboard chassisassembly of the present invention, taken substantially along the line8-8 in FIG. 6;

FIG. 9 is an enlarged transverse section through the keyboard chassisassembly of the present invention, taken substantially along the line9-9 in FIG 6;

FIG. 10 is an enlarged transverse section through the keyboard chassisassembly of the present invention, taken substantially along the line10-10 in FIG. 6;

FIG. 11 is a perspective view of the most preferred form of keyboard ofthe present invention which constitutes an improvement over theembodiment shown in FIGS. 1-10;

FIG. 12 is a vertical longitudinal sectional view through one of the keyunits of the keyboard of FIG. 11, taken substantially along section line12-l2 therein on an enlarged scale;

FIG. 13 is a perspective view of the front end portion of one of thecontrol levers of the keyboard of FIGS. 11 and 12;

FIG. 14 is an enlarged transverse sectional view through a portion ofthe keyboard, as taken substantially along the line 14-14 in FIG. 12;and

FIG. 15 is a perspective view in partial section of a modification ofthe shape of the rear of the chassis member which provides increasedrigidity of the key assembly.

Referring now to the embodiment of the invention shown in FIGS. 1-10,the keyboard chassis assembly of the present invention there showncomprises an elongated chassis member 2 supported on legs 4-, and aplurality of key units 6 supported in longitudinally spaced relationupon the chassis member 2 to form a conventional organ or accordionkeyboard. The chassis member 2 and the inner end portions of the keyunits 6 to be described are normally hidden from View within a cabinetor housing (not shown). Each key unit comprises a left or right handwhite key piece 6a or 6b or a black key piece 7, and a lever arm 8a or8b, the front portion of which is overlaid by the key piece involved.The left hand white key piece 6a is shaped to extend partway around thefront portion of a black key piece '7, and the right hand white keypiece 61) is shaped to extend partway around the front portion of ablack key piece in the usual manner. The present invention relates tothe construction and arrangement of the chassis member and itsrelationship to the key units which result in a unique, rugged, andsimple keyboard chassis assembly. Another feature of the invention isrelated to the construction and relationship of key pieces and theirlever arms.

The chassis member 2 is made of a single sheet metal stamping having amain, generally horizontal, rectangular panel section 19 having a narrowdepending skirt or flange 12 extending for substantially the full lengthof the front longitudinal margin of the chassis member, and an upwardlyextending marginal fulcrum-forming wall 14 extending for substantiallythe full length of the rear longitudinal margin of the chassis member. Aseries of upwardly projecting, longitudinally spaced fingers 16 prodject upwardly from a horizontal upper marginal edge 18 of thefulcrum-forming wall 14. A series of longitudinally spaced fingers 23'are struck upwardly from the front longitudinal margin of therectangular panel section 10, the latter fingers respectively being intransverse alignment with the rear fingers 116.

A series of longitudinally spaced threaded apertures 22 are tapped inthe rear portion of the rectangular panel section it) at a point spacedfrom the fulcrum-forming Wall 14. The threaded apertures 22 arerespectively in alignment with the associated pairs of front and rearchassis fingers l6 and 2h. Spring anchoring lugs 24 (FIGS. 6, 7 and 8)are struck downwardly and rearwardly from the rear margin of thehorizontal panel section 10.

The chassis 2 is preferably elevated above a support surface in thehousing (not shown) of the organ or accordion by suitable legs which maycomprise an angle member secured by screws 28 (FIG. 6) to the frontflange 12 of the chassis member and channel shaped members 3d secured byscrews to the rear portion of the chassis member.

As above indicated, the keyboard 6 supported on the chassis 2 includes aseries of key units each formed of a key piece 6a, 6b, or 7 and anassociated lever arm 811, or 3b. The lever arms 8:: associated with thewhite key pieces 6:! or 611 are somewhat longer than the lever arms 3bassociated with the black key pieces 7.

Each of the lever arms is most advantageously made of a channel-shapedsheet metal stamping having a pair of flanges 3l-34 depending from themargins of a web 36. The depth of the flanges gradually increases towardthe front end of the lever arm and the rear portion thereof has adownwardly offset portion 33 which cooperates with the operatinginstrumentalities of the musical instrument involved. To this end, theoffset portion 33 may be provided with one or more openings 4% forreceiving suitable connecting links (not shown).

The web of each lever arm is provided with a threaded opening 4-2, anopening 4-4 positioned a short distance rearwardly of the threadedopening 42, and a transverse slot positioned a short distance rearwardlyof the opening A pair of inverted V-shaped indentations are formed inthe bottom marginal edges of the side flanges Tad-34 at a point oppositethe slot 46 to form fulcrum points for pivotally supporting the leverarm 8 in the manner to be described upon the chassis member 2. A springanchoring lug is struck downwardly and rearwardly from the web 36 of thelever arm at a point located a short distance rearwardly of the slot 46.The side flanges 3434 of the lever arm terminates a short distancerearv/ardly of the front marginal edge of the web 36 to form thereby ahorizontally, forwardly extending tongue 5%.

Each white key piece 60 or 6b comprises a body of suitable material,such as a white thermoplastic material, having a hollow configurationformed by a top wall 52 which overlies the associated lever arm web 36and depending side walls which straddle the associated lever arm flanges34 This thermoplastic material, for example, may be an acrylic orbutyrate resin. The front end portion of each key piece da or 6b isprovided with a downwardly extending rib 55 having a T-shapcd slot 56(FIG. 3) at the upper extremity thereof adjacent the bottom surface ofthe top wall 52. The head portion 560 of the slot 56 is sized snugly toreceive the tongue 50 at the front end of the associated lever arm 8a,which anchors the front end of the white key piece involved to the leverarm. The rear end portion of the key piece 6a or 612 may be fixedlyanchored to the lever arm by means including a screw as passing througha hole 62 at the rear end of the top wall 52 of the key piece andthreading into the threaded opening in the associated lever arm 8a. Akey piece may be readily removed from a lever arm by unscrewing thescrew 60 and then pulling forwardly on the key piece to pull the leverarm tongue 50 out of the head portion 56a of the slot 56.

The black key pieces are made of any suitable material, most preferablya black thermoplastic material, formed into a hollow member having abase portion defined by vertical side Walls 63 and a flat rear top wallpor tion 65, and an upper portion formed by generally upwardly andinwardly inclining side walls 666d having a top wall 67 well above thelevel of the top wall 52 of the adjacent white key pieces, are clearlyshown in FIG. 1-0 when the black key piece is placed over the frontportion of the associated lever :a-rm 8b, the base sidewalls 6363straddle the flanges 34-34 of the associated lever arm and the web 36 ofthe lever arm bears against the bottom end of a pair of ribs 69-69projecting from the inside surface of the black key piece. The tongue atthe front end of the lever arm Sb passes into a horizontal slot 71formed in an internally projecting portion 73 on the inside of the blackkey piece. The rear end portion of the black kcy piece is anchored inplace by means including a screw 75 which passes through an opera ing 77for-med in the rear top wall portion 65 of the key piece and threadinginto the threaded opening 42 of the lever arm 3b.

As shown most clearly in FIGS. 1, 6 and 7, the various key units aremounted transversely of the chassis member 2 with the flanges 3434 ofthe lever arms 8a and 3b straddling the respective corresponding pairsof front and rear chassis fingers 16 and 2t}. Sleeves 78 made of a softnoise-deadening material which may be a pliable synthetic plasticmaterial is preferably placed around each front chassis finger 23. Therear chassis fingers :16 pass freely through the various transverseslots 46 in the lever arm webs 36 and the adjacent inverted V-shapedflange indentations 49 receive the top marginal edge 18 of thefulcrum-forming wall 14 with the apexes of the latter indentationsforming fulcrum points which p-ivotally support the key units.Sufficient clearance exists between the front and rear of the fingers 16and the defining walls of the slots 46 that the fingers never touch theslot walls for all positions of the key units. There is preferably noclearance between the fingers and the sides of the slot walls. The keyunits are spring biased by individual tension spring members 76extending between the spring anchoring lugs 48 and 24 respectivelystruck from the lever arms and the chassis member. The front ends of thekey units are thereby biased upwardly. The upward movement of each keyunit is limited by adjustable stop means comprising a screw 80 having athreaded shank portion passing through the web opening 44 in theassociated lever arm web and threading into the corresponding threadedaperture 22 formed in the horizontal panel section 1d of the chassismember. The screw St} has a head 32 overlying the associated lever ar-mweb 36 and bearing down upon a metal Washer 83 and a subjacent feltwasher 86 which are sandwiched between the screw head 82 and the leverarm web 36. The adjusted position of the screw 86 is fixed by anysuitable means, such as a lock nut 84 threaded around the bottom end ofthe screw shank 80' below the chassis member 2.

The bottom edges of the lever arm flanges 34-34 project a small distancebelow the bottom edges of the side walls of the various key pieces asshown in FIGS. 6 and 7. Contact between the flanges of the lever armsand the chassis member 2 is prevented by means of a strip of felt 86 orother similar noise-deadening material adhesively or otherwise securedto the front marginal edge portion of the rectangular panel section 16of the chassis member.

Refer now to the embodiment of the invention illustrated in FIGS. 11through 14 which represents the most preferred form thereof. In general,the construction of the individual key units 6 is the same as that shownand described in connection with the embodiment of FIGS. 1 throughexcept for one diiference to be explained, and similar referencenumerals have been used for correspending parts thereof. The chassismember 2, however, has been modified to a substantial extent. Thechassis member 2' has a hollow frame construction rather than the flatpanel construction of the chassis 2 previously described. The chassis 2'has front and rear marginal walls 12 and 14 which respectively haveoutwardly extending horizontal flanges and 92 having screw holes 91 foranchoring the chassis to a suitable portion of the housing or frame (notshown) of the musical instrument involved. Frame 2 also has side or endWall members 9496 respectively extending between the end portions of thefront and rear marginal walls 12' and 14. Bracing members 98 and $9 areshown extending between medial portions of the front and rear walls 12,and 14 to impart strength and rigidity to the chassis member.

The rear marginal wall 14' has fingers 16' extending upwardly from thetop marginal edge 18' thereof which respectively serve the same functionas the fingers 16 and the marginal edge 18 described in connection withthe embodiment of FlGS. 1 through 10. Reaiwardly extending springanchoring lugs 24' are struck from the rear marginal wall 14 at pointsbelow the respective finger 16 to serve as anchoring points for thebottom ends of the springs 76 which spring bias the key units 6.

One of the most important features of the chassis member 2 now beingdescribed is the construction of upwardly extending, longitudinallyspaced fingers 20' extending upwardly from the top marginal edge 21 ofthe front marginal wall 12. The fingers 29 have one function which issimilar to the fingers 20 previously described in that they limitlateral movement of the key units. The fingers 2d are thus positionedopposite the corresponding fingers 16' on rear marginal wall 14' and arestraddled by the flanges 34-34 of the key units. The fingers 2t) areeach bent back at the upper portions thereof to provide rear extensions160. The rear extensions 1% extend generally in a horizontal plane butmay be bent upwardly or downwardly a small amount for reasons to beexplained. Each of the rear finger extensions 100 is encased by a loopor sleeve of noise-deadening material 102 which may be felt or othersimilar material. The fe1t-covered finger extensions 10th serve aselevation adjusting and limiting means as well as lateral stops. To thisend, each of the control levers of the key units is provided withinturned lugs 103-103 projecting from the bottom of the side flanges34-34 thereof a short distance from the front ends of the lever arms, asshown most clearly in FIG. 13. The lugs 1d21tl2 together form ahorizontal abutment shoulder at the bottom of the lever arm which abutagainst the bottom portion of the felt-covered finger extensions 1% tothus limit the upward movement of the key unit involved. Sulficientclearance is provided above the feltcovered finger extensions to permitthe necessary downward movement of the key unit involved.

Refer now to FIG. 15 which shows a modification in the shape of the rearchassis fingers 16" and the top marginal edge 18" of the chassis memberresulting in increased rigidity of the key pieces and decrease in keynoise. The fingers 16" are narrower than the previously describedfingers 16 and 16 so that the fingers do not rub against the insidesurfaces of the lever arm flanges 3434. The lever arm web slot 46' isshortened so that the narrower fingers 16" touch the sides thereof. Moreimportantly, the top marginal edge 18 is provided with pairs of slots1051tl5 into which the lever indentations 49-49 extend to impederelative lateral movement between the lever arm flanges and the chassismember. Each of the slots has a downwardly and inwardly inclining outeredge 105a, a narrow horizontal bottom edge ltlSb of the Width of thelever arm flanges 3434 and a vertical inner edge 105c.

It is apparent that the various forms of the invention described aboveprovide extremely compact, rugged, simple and inexpensive keyboardchassis assemblies for musical instruments. The individual key units areso constructed that the outer key pieces may be readily separated fromthe associated control levers without requiring removal of the entirekey unit from the associated chassis member. Moreover, because of therelationship between the key pieces made of thermoplastic material andthe. channel-shaped lever arms, the key pieces maintain their shapeindefinitely, and the manner in which the key units are mounted upon thechassis member enables the quick and easy assembly of the keyboard.Also, with regard to the improved embodiment of the invention shown inFIGS. 11 through 14, the unitary lateral stop and elevation limitingmeans provides a relatively rigid, simple and effective means formaintaining the proper position and elevation of the key units.

It should be understood that numerous modifications may be made of thepreferred forms of the invention described above without deviating fromthe broader aspects of the invention.

What is claimed and desired to be protected by Letters Patent of theUnited States is:

l. A musical instrument keyboard chassis assembly including incombination, a chassis member having a first series of upwardlyprojecting longitudinally spaced fingers at the front portion thereofand an upstanding fulcrum-forming wall at the rear portion thereofhaving a horizontal upper marginal edge, said upstanding,fulcrum-forming wall having a second series of longitudinally spacedfingers projecting upwardly from said hori zontal upper marginal edgeand respectively positioned in transverse alignment to said first seriesof fingers, said chassis member having spring anchoring means below eachof said second series of fingers; and a set of transversely extending,longitudinally spaced key assemblies movably supported upon said chassismember and forming a keyboard, each of said key assemblies including anelongated channel-shaped lever arm extending between and beyond a pairof the corresponding chassis fingers at the front and rear of saidchassis member which fingers fix the position of the lever arm, saidlever arm having a web portion and downwardly extending marginal flangesfulcrumed on said upper marginal edge of said fulcrum-forming wallpivotally to support the lever arm, and spring means extending betweensaid spring anchoring means below each of said rear chassis fingers andthe associated lever arm at a point rearwardly of the latter finger tobias the front end of each lever arm upwardly, said lever arms includingstop means cooperating with said first series of spaced fingers to limitvertical and lateral movement of said lever arms.

2. A unitary musical instrument keyboard chassis assembly comprising achassis member having a first series of upwardly projecting,longitudinally spaced fingers at the front portion thereof and anupstanding, fulcrumforming wall at the rear portion thereof having ahorizontal upper marginal edge, said upstanding fulcrumforming Wallhaving a second series of longitudinally spaced fingers projectingupwardly from said horizontal upper marginal edge and respectivelypositioned in transverse alignment to said first series of fingers, saidchassis member having spring anchoring means extending from saidfulcrum-forming wall below each of said second series of fingers; and aset of transversely extending, longitudinally spaced key assembliesmovably supported upon said chassis member and forming a keyboard, eachof said key assemblies including an elongated channelshaped lever armextending between and beyond a pair of the corresponding chassis fingersat the front and rear of said chassis member and having marginal flangesextending downwardly from a connecting web, the flanges of each leverarm straddling the associated front and rear chassis fingers which fixthe position of the lever arm, the bottom of the lever arm fianges whichstraddle each rear chassis finger having corresponding inverted V-shapedindentations therein forming fulcrum points which engage over the saidupper marginal edge of said fulcrum-forming wall to pivotally supportthe lever arm, and a tension spring extending between said springanchoring means below each of said rear chassis fingers and theassociated lever arm at a point rearwardly of the latter finger to biasthe front end of each lever arm upwardly, said lever arms including stopmeans cooperating with said first series of spaced fingers to limitvertical and lateral movement of said lever arms.

3. A keyboard chassis assembly fora musical instrument including incombination, a chassis member having a first series of upwardlyprojecting, longitudinally spaced fingers at the front portion thereofand an upstanding, fulcrumforming wall at the rear portion thereofhaving a horizontal upper marginal edge, said upstanding fulcrumformingwall having a second series of longitudinally spaced fingers projectingupwardly from said horizontal upper marginal edge and respectivelypositioned in transverse alignment to said first series of fingers, saidchassis member having spring anchoring means extending from saidfulcrum-forming wall below each of said second series of fingers; and aset of transversely extending, 1ongitudinally spaced key assembliesmovably supported upon said chassis member and forming a keyboard, eachof said key assemblies including an elongated channel-shaped lever armextending between and beyond a pair of the corresponding chassis fingersat the front and rear of said chassis member and having marginal flangesextending downwardly from a connecting web, the flanges of each leverarm straddling the associated front and rear chassis fingers which fixthe position of the lever arm, and the rear portion of the connectingweb thereof having a fingerreceiving opening through which theassociated rear chassis finger extends, the bottom edges of the leverarm flanges which straddle each rear chassis finger being fulcrumed onsaid upper marginal edge of said fulcrumforming wall to pivotallysupport the lever arm, a tension spring extending between said springanchoring means below each of said rear chassis fingers and theassociated lever arm at a point rearwardly of the latter finger to biasthe front end of each lever arm upwardly, said first series of spacedfingers cooperating with said marginal flanges of said lever arms tolimit lateral movement of said lever arms, and adjustable stop meanscooperating with said lever arms for adjusting the vertical pivotablemovement. thereof.

4. A keyboard chassis assembly for a musical instrument including incombination, a chassis member having a generally horizontal panelsection from the front portion of which upwardly extends a first seriesof longitudinally spaced fingers and from the rear portion of whichupwardly extends a fulcrum-forming wall, said fulcrumforming wall havinga second series of longitudinally spaced fingers projecting upwardlyfrom a horizontal upper marginal edge thereof and respectivelypositioned in transverse alignment to said first series of fingers, saidhorizontal panel section of the chassis member having spring anchoringmeans at the base of said fulcrumforming wall below each of said secondseries of fingers, said horizontal panel section of the chassis memberhaving a threaded aperture positioned forwardly of said fulcrum-formingwall and opposite each of said second series of fingers; and a set oftransversely extending key assemblies movably supported upon saidchassis member and forming a keyboard, each of said key assembliescomprising an elongated channel-shaped lever arm extending between andbeyond a pair of corresponding chassis fingers at the front and rear ofsaid chassis member and having marginal flanges extending downwardlyfrom a connecting web, the flanges of each lever arm straddling theassociated front and rear chassis fingers which fix the position of thelever arm, said flanges of each lever arm cooperating with theassociated front chassis finger for limiting lateral movement of saidlever arm, the rear portion of the connecting web of each of said leverarms having a finger-receiving opening which receives the associatedrear chassis finger, the bottom edges of the lever arm flanges whichstraddle each rear chassis finger having corresponding inverted V-shapedindentations therein forming fulcrum points which engage over the saidupper marginal edge of said fulcrum-forming wall pivotally to supportthe lever arm, a tension spring extending between said spring anchoringmeans below each of said rear chassis fingers and the associated leverarm at a point rearwardly of the latter finger to bias the front end ofeach lever arm upwardly, adjustable stop means for adjusting the normalposition of the lever arm comprising a screw having a shank portionpassing through the web of each lever arm and threading into one of saidthreaded apertures in said chassis member and a head portion on top ofsaid web, a noise-deadening washer sandwiched between said screw headportion and said web, and a lock nut threaded around said screw shankportion for locking screw in any of its adjusted positions, each keyassembly having a hollow key piece overlying the front portion of eachlever arm and including depending flanges straddling the flanges of thelever arm, and means removably anchoring each key piece to said leverarm, and a strip of sound deadening material mounted on the key of thefront portion of said horizontal panel section of the chassis memberagainst which material the bottom of said key assemblies bear when fullydepressed.

5. A keyboard chassis assembly for a musical instru ment including incombination, a chassis member having a generally horizontal panelsection from the front portion of which upwardly extends a first seriesor" longitudinally spaced fingers and from the rear portion of whichupwardly extends a fulcrum-forming wall, said fulcrumfo-rming wallhaving a second series of longitudinally spaced fingers projectingupwardly from a horizontal upper marginal edge thereof and respectivelypositioned in transverse alignment to said first series of fingers, saidhorizontal panel section of the chassis member having spring anchoringmeans at the base of said fulcrumforming wall below each of said secondseries of fingers, said horizontal panel section of the chassis memberhaving a threaded aperture positioned forwardly of said fulcnlm-formingwall and opposite each of said second series of fingers; and a set oftransversely extending key assemblies movably supported upon saidchassis member and forming a keyboard, each of said key assembliescomprising an elongated channel-shaped lever arm extending between andbeyond a pair of corresponding chassis fingers at the front and rear ofsaid chassis memher and having marginal flanges extending downwardlyfrom a connecting web, the flanges of each lever arm straddling theassociated front and rear chassis fingers which fix the position of thelever arm, said marginal flanges cooperating with said front chassisfingers to limit lateral movement of said lever arms, said rear portionof the connecting web of each of said lever arms having afinger-receiving opening which receives the associated rear chassisfinger, the bottom edges of the lever arm flanges which straddle eachrear chassis finger having corresponding inverted V-shaped indentationstherein forming fulcrum points which engage over the said upper marginaledge of said fulcrum-forming wall pivotally to support the lever arm, atension spring extending between said spring anchoring means below eachof said rear chassis fingers and the associated lever arm at a pointrearwardly of the latter finger to bias the front end of each lever armupwardly, and adjustable stop means for adjusting the normal position ofthe lever arm comprising a screw having .a shank portion passing throughthe web of each lever arm and threading into one of said threadedapertures in said chassis member and a head portion on top of said web,a noise-deadening washer sandwiched between said screw head portion andsaid web, and a lock nut threaded around said screw shank portion forlocking screw in any of its adjusted positions.

6. A keyboard chassis assembly for a musical instrumerit including incombination, a chassis member having a generally horizontal panelsection from the front portion of which upwardly extends a first seriesof longitudinally spaced fingers and from the rear margin of whichupwardly extends a fulcrum-forming wall, said fulcrumforming wall havinga second series of longitudinally spaced fingers projecting upwardlyfrom a horizontal upper marginal edge thereof and respectivelypositioned in transverse alignment to said first series of fingers, saidhorizontal panel section of the chassis member having spring anchoringmeans at the base of said fulcrumforming wall below each of said secondseries of fingers, said horizontal panel section of the chassis memberhaving a threaded aperture positioned forwardly of said fulcrum-formingwall and opposite each of said second series of fingers; and a set oftransversely extending key assemblies movably supported upon saidchassis member and forming a keyboard, each of said key assembliescomprising a lever arm extending between and beyond a pair ofcorresponding chassis fingers at the front and rear of said chassismember which fingers fix the position of the lever arm, each of saidlever arms having a web portion and marginal flanges extendingdownwardly from said web portion and cooperating with the associatedfront chassis finger to limit lateral movement of said lever arm, eachof said lever arms being fulcrumed over the said upper marginal edge ofsaid fulcrum-forming wall pivotally to support the lever arm, a tensionspring extending between said spring anchoring means below each of saidrear chassis fingers and the associated lever arm at a point rearwardlyof the latter finger to bias the front end of each lever arm upwardly,and adjustable stop means for adjusting the normal position of the leverarm comprising a screw having a shank portion passing through each leverarm and threading into one of said threaded apertures, and a headportion on top of the lever arm, a noise-deadening washer sandwichedbetween said screw head portion and said lever arm, and a lock nutthreaded around said shank portion for locking screw in any of itsadjusted positions.

7. A musical instrument keyboard chassis assembly comprising: chassismeans having a series of upwardly projecting, longitudinally spaced,front key positioning fingers and rear fulcrum-forming means; and a setof transversely extending, longitudinally spaced key assemblies movablysupported upon said chassis means and forming a keyboard, each of saidkey assemblies including an open-bottom channel-shaped lever arm havinga web portion and a pair of spaced marginal side walls extendingdownwardly from said web portion, the rear end portion of each lever armbeing pivotally mounted upon said fulcrum-forming means and the frontend portion thereof fitting over the top of one of said frontkeypositioning fingers, said side walls of each lever arm cooperatingwith the associated front finger to limit lateral movement of said leverarm, spring means extending between each of said lever arms at a pointbehind said fulcrum-forming means and said chassis means to bias thefront end portion of each lever arm upwardly, and means limiting theelevation of the front end portion of each lever arm comprising alateral extension on the associated front key-positioning finger of thechassis means and a stop shoulder on the inside of the lever arm whichabuts against the bottom of the associated finger extension when thefront end portion of the lever arm reaches the desired elevation, andthere being a clearance space above each finger extension inside eachlever arm to permit the necessary downward movement of the lever arm.

8. A musical instrument keyboard chassis assembly comprising: chassismeans having a series of upwardly projecting, longitudinally spacedfront key-positioning fingers and rear fulcrum-forming means; and a setof transversely extending, longitudinally spaced key assemblies movablysupported upon said chassis means and forming a keyboard, each of saidkey assemblies includaosases ing a channel-shaped metal lever arm havinga web portion and marginal flanges extending downwardly therefrom, saidlever arm having a rear end portion pivotally supported upon saidfulcrum-forming means and a front end portion straddling the top of oneof said front keypositioning fingers, said marginal flanges of eachlever arm cooperating with the associated key positioning finger tolimit the lateral movement of the lever arm, said lever arm projectingbeyond the associated key-positioning finger, resilient means for urgingthe front end portion of the associated lever arm upwardly, and meanslimiting the elevation of the front end portion of each lever armcomprising a lateral extension on the associated keypositioning fingerwhich lateral extension is surrounded by .a noise-deadening material anda stop shoulder extending inwardly from one marginal flange of theassociated lever arm which abuts against the bottom of the associatedfinger extension when the front end portion of the lever arm reaches thedesired elevation, there being clearance provided above said fingerextension permitting the necessary downward movement of the lever arm.

9. A musical instrument keyboard chassis assembly comprising: chassismeans having a series of upwardly projecting, longitudinally spacedfront key-positioning fingers and rear fulcrum-forming means; and a setof transversely extending, longitudinally spaced key assemblies movablysupported upon said chassis means and forming a keyboard, each of saidkey assemblies including a channel-shaped metal lever arm with a webportion and marginal flanges extending downwardly therefrom, said leverarm having a rear end portion pivotally supported upon saidfulcrum-forming means and a front end portion straddling the top of oneof said front keypositioning fingers, said marginal flanges of eachlever arm cooperating with the associated front key positioning fingerto limit the lateral movement of the lever arm, resilient means forurging the front end portion of the associated lever arm upwardly, andmeans limiting the elevation of the front end portion of each lever armcomprising a lateral extension on the associated key-positioning fingerand a stop shoulder 011 the associated lever arm which abuts against thebottom of the associated finger extension when the front end portion ofthe lever arm reaches the desired elevation, there being clearanceprovided above said finger extension permitting the nee essary downwardmovement of the lever arm.

10. A keyboard chassis assembly for a musical instru ment keyboardcomprising a chassis member having a main generally horizontal panelsection from the front margin of which is struck a first series ofupwardly projecting, longitudinally spaced fingers and from the rearmargin of which there extends an upstanding marginal fulcrum-formingwall, said upstanding, marginal fulcrumforming wall having a secondseries of longitudinally spaced fingers projecting upwardly from ahorizontal upper marginal edge thereof and respectively positioned intransverse alignment to said first series of fingers, said horizontalpanel section of the chassis member having a spring anchoring lug struckfrom the rear portion thereof below each of said second series offingers, and a set of transversely extending key assemblies movablysupported upon said chassis member and forming a keyboard, each of saidkey assemblies comprising an elongated channel-shaped lever arm having aWeb portion and marginal flanges extending downwardly therefrom, each ofsaid lever arms extending between and beyond a pair of correspondingchassis fingers at the front and rear of said chassis member whichfingers fix the position of the lever arm and the rear portion thereofhaving a finger-receiving opening which receives the associated rearchassis finger, and the bottom of the lever arm being fulcrurned overthe said upper marginal edge of said fulcrum-forming wall pivotally tosupport the lever arm, and a tension spring extending between saidspring anchoring lug below each of said rear chassis fingers and theassociated lever arm at a all) l2 point rearwardly of the latter fingerto bias the front end of each lever arm upwardly, said lever arms havingstop means cooperating with said chassis member to limit vertical andlateral pivotal movement of said key assemblies.

11. A musical instrument keyboard chassis assembly comprising a chassismember having an upstanding, fulcram-forming wall at the rear portionthereof with a horizontal upper marginal edge and a series oflongitudinally spaced fingers projecting upwardly from said horizontalupper marginal edge, said chassis member having positioning means at thefront portion thereof, and a set of transversely extending,longitudinally spaced key assemblies movably supported upon chassismember and forming a keyboard, each of said key assemblies including anelongated channel-shaped lever arm having marginal flanges extendingdownwardly from a connecting web, the flanges of each lever armstraddling one of the rear chassis fingers which fix the position of thelever arm, and a pair of slots formed in said horizontal marginal edgeof said chassis member on opposite sides of each of said fingers andpositioned snugly to receive the bottoms of the associated lever armflanges and pivotally support the lever arms, each of said lever armshaving stop means cooperating with said positioning means to limitvertical and lateral pivotable movement of the lever arm.

12. A musical instrument keyboard chassis assembly comprising a chassismember having an upstanding, fulcrum-forming wall at the rear portionthereof with a horizontal upper marginal edge and a series oflongitudinally spaced fingers projecting upwardly from said horizontalupper marginal edge, said chassis member having upwardly projectinglongitudinally spaced positioning fingers at the front portion thereof,and a set of transversely extending, longitudinally spaced keyassemblies movably supported upon said chassis member and forming akeyboard, each of said key assemblies including an elongatedchannel-shaped lever arm having marginal flanges extending downwardlyfrom a connecting Web, the flanges of each lever arm straddling one ofthe chassis fingers which fix the position of the lever arm, and a pairof slots formed in said horizontal marginal edge of said chassis memberon opposite sides of each of said fingers and positioned snugly toreceive the bottoms of the associated lever arm flanges, the bottom ofthe lever arm flanges which straddle each rear chassis finger havingcorresponding inverted V-shaped indentations at the points thereof whichpass into said slots to form fulcrum points which engage the bottomdefining Walls of said slots pivotally to support the lever arm, each ofsaid channel-shaped lever arms having stop means thereon cooperatingwith the associated positioning finger to limit vertical and lateralpivotable movement of said lever arm.

13. A key assembly for musical instrument keyboard which has guide meansfor the keys thereon, said assembly including in combination, ahorizontally elongated channel-shaped metal lever arm having a web atthe top thereof and depending longitudinal flanges at the sides thereof,said lever arm having a rear portion adapted to be pivotally mounted anda front portion with a projection extending from the bottom of at leastone of said flanges, said web and flanges of said front portion of saidlever arm and said projection being arranged to surround the guide meansto limit the upward, downward and lateral movement of the front portionof said lever arm, and a hollow, open-bottom, thin-Walled key piece madeof plastic material secured to said lever arm, said key piece havingside walls extending along and straddling the flanges of said lever arm.

14. A musical instrument keyboard chassis assembly including incombination: chassis means having a series of upwardly projecting,longitudinally spaced, front key positioning fingers and rearfulcrum-forming means; and a set of transversely extending,longitudinally spaced key assemblies movably supported upon said chassismeans and forming a keyboard, each of said key assembles including achannel-shaped metal lever arm having a pair of spaced side walls, eachof said lever arms having a rear portion pivotal-1y mounted upon saidfulcrumform-ing means and a front portion fitting over the tor of one ofsaid front key-positioning fingers, said key-positioning fingerscooperating with said side walls of said lever arms to limit lateralmovement thereof, spring means extending between each of said lever armsand said chassis means at a point behind said fulcrum-forming means tobias said front portion of each lever arm upwardly, each of said frontkey-positioning fingers of said chassis means having a lateralextension, each of said lever arms having a portion projecting from thebottom of at least one of said side walls thereof and positioned toengage said lateral extension to limit the elevation of said frontportion of said lever arm, said lateral extensions being positioned topermit downward movement of said lever arms, and a hollow, open bottomplastic key piece secured to each lever arm, said key pieces having sidewalls etXending along the side walls of said lever arms.

15. A musical instrument keyboard chassis assembly including incombination: chassis means having a series of upwardly projecting,longitudinally spaced, front key positioning figures each having alateral extension, said chassis means also having pivot means positionedrearwardly of said positioning fingers and a set of transverselyextending, longitudinally spaced key assemblies movably support-ed uponsaid chassis means and forming a keyboard, each of said assembliesincluding a channel-shaped metal lever arm having a web at the topthereof and depending flanges at the sides thereof, each of said leverarms having a rear portion thereof mounted upon said pivot means and afront portion thereof fitting over said lateral extension of one of saidfront key-positioning fingers, said pivot means including spaced slotsfor receiving the side flanges of each lever arm, spring means extendingbetween each of said lever arms and said chassis means at a point behindsaid pivot means to bias said front portion of each lever arm upwardly,each of said lever arms having a portion projecting from the bottom ofat least one of said side flanges thereof into the space between saidside flanges and positioned to engage said lateral extension to limitthe elevation of said front portion of said lever arm, said web andflanges of said front portion of each lever arm and said projectingportion thereof being arranged to surround said lateral extension of the"associated positioning finger to limit the upward, downward and lateralmovement of said front portion of said lever arm, and a hollow, openbottom plastic key piece secured to each lever arm, said key pieceshaving side walls extending along and straddling the side flanges ofsaid lever arms.

16. A key for keyboard musical instruments comprising an elongatedchannel-shaped member, said member having'a web portion and marginalflanges adapted to extend downwardly from said Web portion, pivot meansadjacent one end of said member operatively associated with said web andflanges, and stop means adjacent the opposite end of said member adaptedto coact with a fixed member to limit vertical and lateral pivotalmovement of said key.

17. A musical instrument keyboard chassis assembly including incombination, chassis means having a series of upwardly projecting,longitudinally spaced, front key positioning fingers, said chassis meansalso having pivot means positioned rearwardly of said positioningfingers, and a set of transversely extending, longitudinally spaced keyassemblies movably supported upon said chassis means and forming akeyboard, each of said key assemblies including an elongatedchannel-shaped metal lever arm extending between said pivot means andsaid positioning fingers, each of said lever arms having a portionthereof pivotally supported by said pivot means and a front portion withdownwardly extending side flanges extending over one of said keypositioning fingers, tension means extending between each of said leverarms and said chassis at a point behind said pivot means to bias saidfront portion of each lever arm upwardly, stop means for limiting thevertical and lateral movement of said front portion of each of saidlever arms including noise deadening material about said key positioningfingers and cooperating with said side flanges of said lever arms torestrict lateral movement thereof, and a hollow open bottom plasic keypiece secured to each lever arm, each of said key pieces having sidewalls extending along and straddling said side flanges of one of saidlever arms.

18. The keyboard chassis assembly of claim 17 including resilient meanson said chassis means positioned to be engaged by said flanges of thefront portion of each of said lever arms for limiting downward movementof each of said key assemblies.

19. The assembly of claim 17 wherein each of said key positioningfingers has a lateral extension and each of said lever arms has ashoulder portion projecting from the bottom of at least one of said sideflanges thereof into the space between said side flanges, with themaximum upward movement of the front portion of each of said lever armsbeing limited by engagement of said shoulder thereof with said noisedeadening material on said lateral extension of said associated keypositioning finger.

20. A musical instrument keyboard chassis assembly including incombination; chassis means having a series of upwardly projecting,longitudinally spaced, front key positioning fingers each having alateral extension, said chassis means also having pivot means positionedrearwardly of said positioning fingers, and a set of transverselyextending, longitudinally spaced key assemblies movably supported uponsaid chassis means and forming a keyboard, each of said assembliesincluding a channelshaped metal lever arm having a web portion at thetop thereof and downwardly extending flanges at the sides thereof, eachof said lever arms having a portion thereof mounted upon said pivotmeans and a front portion thereof fitting over said lateral extension ofone of said front key-positioning fingers, said pivot means includingspaced slots for receiving the side flanges of each lever arm, meansextending between each of said lever arms and said chassis means to biassaid front portion of each lever arm upwardly, each of said lever armshaving a stop portion projecting from the bottom of at least one of saidside flanges thereof into the space between said side flanges andpositioned to engage said lateral extension to limit the elevation ofsaid front portion of said lever arm, said flanges of said front portionof each lever arm and said stop portion thereof being arranged tocooperate with said lateral extension of the associated positioningfinger to limit the lateral and vertical movement of said front portionof said lever arm, and a hollow, open bottom plastic key piece securedto each of said lever arms, said key piece having side walls extendingalong and straddling the side flanges of said lever arm.

21. A key for keyboard musical instruments including in combination, anelongated channel-shaped member having front and rear portions, saidmember having a web portion and marginal flanges adapted to extenddownwardly from said web portion, pivot means on said rear portion ofsaid member operatively associated with said web and flanges, stop meanson said front portion of said member adapted to coact with a fixedmember to limit vertical and lateral pivotal movement of said key, and ahollow plastic key piece overlying said front portion of said lever armand including depending flanges straddling said marginal flanges of saidlever arm, means removably anchoring said key piece to said lever armincluding relatively longitudinally movable engaging connecting means onthe front end portions of said key piece and said lever arm, and screwmeans for securing the rear end portion of said key piece to said leverarm.

22. A key for keyboard musical instruments including enemas incombination, an elongated channel-shaped member having front and rearportions, said member having a web portion and marginal flanges adaptedto extend downwardly from said web portion, pivot means on said rearportion of said member operatively associated with said web and fltnges,stop means on said front portion of said member adapted to coact with afixed member to limit vertical and lateral pivotal movement of said key,and a hollow, open-bottom, thin walled key piece made of a syntheticthermoplastic material, said key piece having side walls snuglystraddling said marginal flanges of said lever arm.

References Cited in the file of this patent UNITED STATES PATENTSHammond May 10, Appel Feb. 5, Greenleaf et a1. Oct. 7, Larsen et al Mar.3, Link Oct. 2, Hayslett Apr. 29,

FOREIGN PATENTS Germany June 23,

16. A KEY FOR KEYBOARD MUSICAL INSTRUMENTS COMPRISING AN ELONGATEDCHANNEL-SHAPED MEMBER, SAID MEMBER HAVING A WEB PORTION AND MARGINALFLANGES ADAPTED TO EXTEND DOWNWARDLY FROM SAID WEB PORTION, PIVOT MEANSADJACENT ONE END OF SAID MEMBER OPERATIVELY ASSOCIATED WITH SAID WEB ANDFLANGES, AND STOP MEANS ADJACENT THE OPPOSITE END OF SAID MEMBER ADAPTEDTO COACT WITH A FIXED MEMBER TO LIMIT VERTICAL AND LATERAL PIVOTALMOVEMENT OF SAID KEY.